The present invention relates to a device for retaining a bobbin case member against rotation, and more particularly to a device for use in a horizontally fully rotatable shuttle for restraining the bobbin case member thereof from rotation and for releasing an upper thread free of resistance.
With bobbin case member retaining devices heretofore known for use in horizontally fully rotatable shuttles, a retainer is adapted to act on two portions of the bobbin case member alternately to assure smooth passage of the upper thread. Since the bobbin case member is retained at alternately changing locations in the case of such devices, the bobbin case member is liable to backlash, consequently making a noise and leading to reduced sewing efficiency.
Additionally the parts must be finished with high dimensional accuracy so that the retainer will act on the bobbin case member at two portions thereof alternately accurately for the retention of the shuttle member. This entails an increase in manufacturing cost.